1. Technical Field
The invention relates to cargo straps, particularly to chain binders.
2. Related Art
A cargo strap is used for securing cargo in a truck to prevent cargo from flying or dropping. A cargo strap needs a binder to tighten. A conventional cargo strap binder is primarily composed of a main tube and two links. Two ends of the main tune are separately provided with two opposite inner threads. The two links are separately provided with two outer threads to be screwed in the main tube. An outer end of each link projects from the main tube. The two links will simultaneously outward stretch from or inward retract in the main tube. Thus the cargo strap can be tightened or loosened.
Such a binder is provided with a gear and a seat. The gear integrally connected on the main tube to be a single piece. The seat is rotatably connected on the main tube and the gear is received in the seat. The seat is further provided with a swingable claw to control rotation of the gear. The claw can be positioned by a claw positioner and adjusted to change relative relation between the claw and gear. A rotatable lever is pivoted on the seat. The claw will rotate the gear and main rube when the lever is pushed toward a specific direction, and the claw and the gear will become neutral when the lever is pushed an opposite direction so as to form a unidirectional ratchet effect.
However, such a binder has some drawbacks. First, the claw is arranged in the seat. When tightening or loosening the strap, the position of the claw must be adjusted to change the ratchet action direction. At this time, the user has to insert his or her finger into the seat to make this adjustment. This is very inconvenient and dangerous for users. Second, the lever must keep perpendicular to the main tube when operating. For the sake of safety, the lever must be rotated 90 degrees to be parallel to the main tube when not operating. However, those conventional binders do not provide any positioning or locking mechanism for the rotatable lever. As a result, the lever may still freely rotate because of vibration of truck transportation. This will be very dangerous.